The Hubble Space Telescope

Unlocking the Secrets of the Universe

Flight Operations Summary

Significant Spacecraft Anomalies: (The following are preliminary reports
of potential non-nominal performance that will be investigated.)
HSTARs:
none
COMPLETED OPS REQUEST:
19263-0 - Clear COS Event Flag 3 for prop 12810 visits 18-19@156/1802z
COMPLETED OPS NOTES:
none
FGS ACQ STATUS:
SCHEDULED SUCCESSFUL
FGS GSAcq 7 7
FGS REAcq 9 9
OBAD with Maneuver 6 6
SIGNIFICANT EVENTS:
The COS FUV Special Recovery activities (proposal 12810 visits 16 - 17) successfully completed
today without incident. The FUV was ramped to the 2nd HV plateau (-5010V/-4963V (160/157)) similar
to visit 10; however this time the QE grid was on, no elevated counts or HV current transients
were observed in the engineering telemetry during or after the ramp. The STScI and MOSES2
Engineering Teams have examined the relevant telemetry and confirmed all voltages, currents and
temperatures were as expected. The voltage and current monitors matched the signatures seen in
SMOV. The COS Science Team at STScI has examined the science data and DCE memory dumps and
everything is nominal. No HV current transients or unexpected elevated count rates were observed
in the DCE memory dumps. The science data consisted of 2 sets of dark and wavecal exposures. The
exposures were collected immediately after ramping to HVNom (160/157) and an hour later at the same
HV level. Comparisons with SMOV data indicates comparable behavior when the aging of the detector
and temporal fluctuations are considered. The Engineering and Science Teams have given a "Go" to
proceed with visit 18 and 19. Visits 18 and 19 are scheduled for Tuesday June 5 (DOY 157). The COS
event flag 3 was cleared @156/18:02 via OR 19263 -jb